Search found 50 matches

by Clemens
1 month ago
Forum: API
Topic: Matrix to GDX from Python
Replies: 3
Views: 269

Re: Matrix to GDX from Python

I can not say anything about csr_matrix in particular, but if possible, you can skip the zeros of any sparse matrix representation when writing to an instance of GamsParameter. Filling data using the Object-oriented Python API always works record based by calling my_symbol.add_record([key1, key2,......
by Clemens
1 month ago
Forum: API
Topic: Matrix to GDX from Python
Replies: 3
Views: 269

Re: Matrix to GDX from Python

Hi, You can represent the matrix as a 2-dimensional GAMS parameter using the following code: from gams import * A=[[0., 0., 0., 0., 0.], [0., 0., 0., 0., 0.], [0., 0., 0., 0., 0.], [0., 0., 0., 1., 0.], [0., 0., 0., 0., 1.]] ws = GamsWorkspace(".") db = ws.add_database('data') mat = db.add_parameter...
by Clemens
6 months ago
Forum: API
Topic: Python 3.7
Replies: 1
Views: 836

Re: Python 3.7

Renger, First of all we need to distinguish between the use of the GAMS Python API and the GAMS Embedded Code Facility . While the GAMS Python API is provided for different version of Python, the Embedded Code Facility requires a Python 3.6 right now. The error message comes from the setup.py script...
by Clemens
8 months ago
Forum: API
Topic: GMSPython 3.7 and tkinter
Replies: 2
Views: 1520

Re: GMSPython 3.7 and tkinter

Hello, There is currently no time schedule for updates of the Python version that is shipped with GAMS. It is primarily meant to be used as a minimal Python interpreter for certain GAMS features, especially the Embedded Code Python Facility. If there is a need for specific Python configurations, a s...
by Clemens
11 months ago
Forum: API
Topic: Python API Exception Handling
Replies: 5
Views: 1121

Re: Python API Exception Handling

This is not possible right now. In order to get detailed information about an error it is required to have a look into the listing file or to examine the log output.

Best,
Clemens
by Clemens
1 year ago
Forum: API
Topic: Python API Exception Handling
Replies: 5
Views: 1121

Re: Python API Exception Handling

The log output can be captured by specifying the output argument in GamsJob.run() . The following code snipped shows how to get the log output redirected to stdout: from gams import * import sys if __name__ == "__main__": if len(sys.argv) > 1: ws = GamsWorkspace(system_directory = sys.argv[1]) else:...
by Clemens
1 year ago
Forum: API
Topic: Python API Exception Handling
Replies: 5
Views: 1121

Re: Python API Exception Handling

Hello, The GamsException itself as well as the GamsExceptionExecution do not give you detailed information about the cause of an error. You can use the GamsException.get_rc() call in order to get the return code of GAMS which tells you what kind of problem occurred. See the documentation for possibl...
by Clemens
1 year ago
Forum: API
Topic: Reusing a model instance in different function calls
Replies: 6
Views: 1418

Re: Reusing a model instance in different function calls

Bruno, Sorry for the delay. It seems to me that you did solve your original problem where you did the mi.instantiate call multiple times. So from a GAMS/Python perspective the code looks actually correct to me. The new problem that arises now is that you also want to do some calculations in MatLab "...
by Clemens
1 year ago
Forum: API
Topic: Reusing a model instance in different function calls
Replies: 6
Views: 1418

Re: Reusing a model instance in different function calls

Bruno, You do not have to call those methods multiple times. After you have instantiated your GamsModelinstance you have also defined the symbols that you want to change (GamsModifier). All you have to do is to change the data in your symbol (ySp) and call mi.solve(). Can you can provide a larger ex...
by Clemens
1 year ago
Forum: API
Topic: Reusing a model instance in different function calls
Replies: 6
Views: 1418

Re: Reusing a model instance in different function calls

Bruno, You might want to have a look at the transport7.py example: https://www.gams.com/latest/docs/apis/examples_python/transport7_8py_source.html This shows how you can use the GamsModelinstance class. More information is available in the documentation: https://www.gams.com/latest/docs/apis/python...